The present invention relates to golf balls and, more particularly, to golf balls comprising one or more metal mantle layers and which further comprise a cellular or liquid core. The golf balls may comprise an optional polymeric outer cover and/or an inner polymeric hollow sphere substrate.
Prior artisans have attempted to incorporate metal layers or metal filler particles in golf balls to alter the physical characteristics and performance of the balls. For example, U.S. Pat. No. 3,031,194 to Strayer is directed to the use of a spherical inner metal layer that is bonded or otherwise adhered to a resilient inner constituent within the ball. The ball utilizes a liquid filled core. U.S. Pat. No. 4,863,167 to Matsuki, et al. describes golf balls containing a gravity filler which may be formed from one or more metals disposed within a solid rubber-based core. U.S. Pat. Nos. 4,886,275 and 4,995,613, both to Walker, disclose golf balls having a dense metal-containing core. U.S. Pat. No. 4,943,055 to Corley is directed to a weighted warmup ball having a metal center.
Prior artisans have also described golf balls having one or more interior layers formed from a metal, and which feature a hollow center. Davis disclosed a golf ball comprising a spherical steel shell having a hollow air-filled center in U.S. Pat. No. 697,816. Kempshall received numerous patents directed to golf balls having metal inner layers and hollow interiors, such as 704,748; 704,838; 713,772; and 739,753. In U.S. Pat. Nos. 1,182,604 and 1,182,605, Wadsworth described golf balls utilizing concentric spherical shells formed from tempered steel. U.S. Pat. No. 1,568,514 to Lewis describes several embodiments for a golf ball, one of which utilizes multiple steel shells disposed within the ball, and which provide a hollow center for the ball.
Prior artisans have attempted to provide golf balls having liquid filled centers. Toland described a golf ball having a liquid core in U.S. Pat. 4,805,914. Toland describes improved performance by removing dissolved gases present in the liquid to decrease the degree of compressibility of the liquid core. U.S. Pat. No. 5,037,104 to Watanabe, et al. and U.S. Pat. No. 5,194,191 to Nomura, et al. disclose thread wound golf balls having liquid cores. Similarly, U.S. Pat. No. 5,421,580 to Sugimoto, et al. and U.S. Pat. No. 5,511,791 to Ebisuno, et al. are both directed to thread wound golf balls having liquid cores limited to a particular range of viscosities or diameters. Moreover, Molitor, et al. described golf balls with liquid centers in U.S. Pat. Nos. 5,150,906 and 5,480,155.
The only known U.S. patents disclosing a golf ball having a metal mantle layer in combination with a liquid core are U.S. Pat. No. 3,031,194 to Strayer and the previously noted U.S. Pat. No. 1,568,514 to Lewis. Unfortunately, the ball constructions and design teachings disclosed in these patents involve a large number of layers of different materials, relatively complicated or intricate manufacturing requirements, and/or utilize materials that have long been considered unacceptable for the present golf ball market.
Concerning attempts to provide golf balls with cellular or foamed polymeric materials utilized as a core, few approaches have been proposed. U.S. Pat. No. 4,839,116 to Puckett, et al. discloses a short distance golf ball. It is believed that artisans considered the use of foam or a cellular material undesirable in a golf ball, perhaps from a believed loss or decrease in the coefficient of restitution of a ball utilizing a cellular core.
Although satisfactory in at least some respects, all of the foregoing ball constructions, particularly the few utilizing a metal shell and a liquid core, are deficient. This is most evident when considered in view of the stringent demands of the current golf industry. Moreover, the few disclosures of a golf ball comprising a cellular or foam material do not motivate one to employ a cellular material in a regulation golf ball. Specifically, there is a need for a golf ball that exhibits a high initial velocity or coefficient of restitution (COR), may be driven relatively long distances in regulation play, and which may be readily and inexpensively manufactured.
These and other objects and features of the invention will be apparent from the following summary and description of the invention, the drawings, and from the claims.
The present invention achieves the foregoing objectives and provides a golf ball comprising one or more metal mantle layers and which further comprise a cellular or a liquid core component. Specifically, the present invention provides, in a first aspect, a golf ball having a cellular or liquid core, and comprising a spherical metal mantle and a polymeric outer cover disposed about and adjacent to the metal mantle. The metal mantle is preferably formed from steel, titanium, chromium, nickel, or alloys thereof. The metal mantle may comprise one or more layers, each formed from a different metal. The polymeric outer cover is preferably relatively soft and formed from a low acid ionomer, a non-ionomer, or a blend thereof.
In a second aspect, the present invention provides a golf ball having a cellular or liquid core component, and comprising an inner polymeric hollow spherical substrate, a spherical metal mantle, and a polymeric outer cover. The spherical metal mantle is disposed between the spherical substrate and the outer cover.
The cellular core is preferably formed from at least one of a polybutadiene/ZDA mixture, polyurethanes, polyolefins, ionomers, metallocenes, polycarbonates, nylons, polyesters, and polystyrenes. The liquid constituting the liquid core material preferably comprises at least one of an inorganic salt, clay, barytes, and carbon black dispersed or mixed with at least one of water, glycol, and oil.
The present invention also provides related methods of forming golf balls having metal mantles and cellular or liquid cores, with or without an inner polymeric hollow spherical substrate or an outer cover.
These and other objects and features of the invention will be apparent from the following detailed description.